Electrical heating unit



Dec.- 21, 1948. M, PARMLEY 2,457,065

ELECTRICAL HEATING UNIT l Filed Dec.. z, 1945 Patented Dec. 21, 1948 U N I TED STATES PATEN T FFl'CE ELECTRICAL HEATING 'UNIT Harry larmley, Harrisburg, Pa. Application December 20, 1945, Serial No. '636,221

- Claims.

This invention relates to 'electrical heating units 'and particularly 'to that -type'of electrical heating unit adapted for use lin the interior -o'f liquid containers.

:One object of the invention 'is Ato provide -an electrical heating vunit of this type which can be removably positioned within the liquid container, the vunit being supported on ythe container closure in such fashion as to 'function with `maximum efiiciencv Another object of the invention is to provide a heating unit of the type indicated which will be efficient in operation by yreason of the provision of comparatively large upper and `lower heat radiating surfaces.

A still further object 'of the invention is to provide an electrical heating unit supported by the closure yfor the container in lwhich the unit is to be used, said unit being provided with breather means to permit the escape of air from the interior of the unit per se when the latter is in use.

With Vthese and other A'objects in view, 'the invention consists incertain details 'of construction and combinations and arrangements of parts, all as will hereinafter 4be more fully Fdescribed 'and the novel features thereof particularly 'pointed out in the appended claims.r i

In the accompanying drawing:

yFigure 1 illustrates the unit 'positioned within 'one type of container, the view being essentially a "sectional view taken 'longitudinally of the container and unit with a portion o'f the container closure being shown in elevation; and

Fig. 2 is a transverse sectional view v'on the line 2-2 of Fig. 1.

The present invention resides primarily in a yheating unit adapted for 'use in lheating liquids in containers Aof different ltypes but in the present 'instance a container of these-'called thermos vvessel 'type is illustrated, said `vessel which is of the double wall type being indicated at i0. The vessel or container has an yopen "upper end for `filling and this opening 'is adapted to Abe Iclosed `With a closure removably positioned therein. While the -conten'ts of the vessel maybe discharged in various ways 'an `outlet I'2 is shown in 'the present instance, said 'outlet :being threaded as at I3 for attachment of a "faucet or Jother discharge control means "(not shown).

Essentially, :the present heatingunitfcomprises `an electrical resistance `element with suitable lead 'connections supported on a `member `of electrical insulating material and a ymetal housing or basing Afor the electrical resistance element 'fan-d vits 'iinsu'iating support, said housing Aand insulating fsupport both beingsecurely vmounted in the closure il ci the vessel so that the unit may readily be installed inA and removed from the vessel merely by placing the closure lin or removing it the lling opening o the vessel. The housing or 'casing -foi "the yelectrical resistance element comprises an 4upper tubular Aportion 'M Ywhose upper end is secured in closure -Ii-I 'by having its upper extremity turned down ush with the ltop surface `of the l'closure 4as indicated at I5, a bead 'i6 bei-ng formed-on the tubular member III diately below the closure so as to prevent tudinai displacement lof the'tubular member. At its v.lower extremlitytheltubular member llmer'ges into Ta cylindrical portion lle which fis essentially a continuation of portion f'i4 but which is of con` `"siderably greater diameter than the tubular lper- Ftion il so that its upper and 'lower walls or "surlfaces constitute comparatively flarge heat lradiating areas because, as will 'be flater explained, the `heat producing rportion vof ythe unit, i. e., the electrical .resistance element iis entirely housed within 'this fcylindricalrportion i4 yof the unit basing.

Arranged concentrically within the tubular member i4' is :an inner tubular member =I1 of infsulating material whose lower `enc'l :is adapted Ito 'support a 'block or body of porcelain or 'other insulating fmat'erial 'in which the electrica-l ref sistance zele'ment 'lB is supported. "Ilhe block tof vporcelain-or other material has a hub `portion i118 termed with la ltransverse irib 210 von its upper surtace in which there are 'two slots for reception-of binder posts 2l, 212 to which the ends of the re'- sistanfce elementare connectedand to which :the lead wires 23-are also connected, said lead `wires Vextending upwardly :through the inner tubulsr .insulating member :Il -to a plug uor socket .24 mounted inthe upper end of that mem-ber. The hub portion I8 is also formed with -an annular recess around its upper edge for .reception of the lower end ofthe tubular lmember `Il and .in -order to take advantage of the comparatively ,largeheat radiating surfaces formed by the uppervand lower walls of rthe lower cylindrical portion Ila of r`the unit 'casing said block of porcelain is formed with a plurality of arms 25 radiating `from the hub I8 and merging .at their outer Vends in an annular ring 26. LIn between said arms `25 `the hub 't8 is also formed `with lugs ''2-f'|` andthe `lugs and arms all .have perforations formed therein through which the electrical resistance velement :can the threaded at `poi-nts radially beyond the tubular members Il, lf'l. In other words, lby lhaving the lower `cylindrical 'portion vIl" of "the basing iof greater cross sectional size than the tubular portion I4 and by mounting the resistance element in the arms and lugs of the porcelain block which may be described as being of spider formation the resistance element can be spread out over` a comparatively large area to take advantage ci the radiating capacity of the lower cylindrical portion Illa of its casing.

In order to maintain the inner insulating member I'I and the porcelain band or ring 26 in proper spaced relation concentrically of the casing and to afford breather means to permit the escape of air when the unit is in use, spacer means in the form of strips or split rings of cork are interposed between those structural parts, as best illustratedin Fig. l. For instance, a split ring or strip of cork 28 is positioned between the upper ends of the two tubular members I4 and I1 and strips or a split ring of cork 29 is interposed between the lower ends of those two tubular members while a third body of cork indicated at 30, which may also be either a split ring or strips, is interposed between the porcelain band 26 and the side wall of the lower cylindrical portion Illa of the casing. Preferably these bodies of cork fit closely between the structural elements and maintain them in proper spaced relation at all times but, at the same time, air may escape through the split rings when current is passed through the electrical resistance unit which results in the air becoming heated and expanding.

The tube II may be of any desired insulating material and, of course, the casing composed of tube I4 and cylindrical portion Me may be of any suitable material although aluminum is preferred. Preferably the length of the two tubes I4, I1 and the depth or height of the cylindrical portion I4a is such that the latter will be spaced an appreciable distance from the bottom of the s container in order to take full advantage of the radiation of heat from the bottom of the portion I4". As stated, the vessel may be of any desired type and the discharge control means, therefore, may take various forms, neither of these elements actually forming any part of the present invention. Also, it is deemed unnecessary to illustrate any of the electrical connections as it will be understood that suitable means will be provided for attaching the heating unit when installed in the container to the usual house current. If desired an arrangement in the form of a steam whistle indicated more or less diagrammatically at 3| may be provided in the closure II to function as a signal when the liquid in the container has reached the boiling point so as to permit the heating unit to be disconnected and thus conserve current.

`What is claimed is:

1. An electrical heating unit adapted to be removably positioned in a liquid container, said unit comprising spaced, concentric inner and outer tubular members mounted at their upper ends in a closure for said container, said inner member being formed of electrical insulating material and said outer member being of metal, spacer members having air passages therein interposed between said inner and outer members,

an electrical heating unit supported at the lower i end of the inner member, lead wires extending through the inner member from said resistance element to the upper end of the inner tubular member, and a cylindrical metal casing for said resistance unit mounted on the lower end of said 2. An electrical heating unit adapted to be removably positioned in a liquid container, said unit comprising spaced, concentric inner and outer tubular members mounted at their upper ends in a closure for said container, said inner member being formed of electrical insulating material and said outer member being of metal, spacer members having air passages therein interposed between said inner and outer members, an electrical heating unit supported at the lower end of the inner member, lead wires extending through the inner member from said resistance element to the upper end of the inner tubular member, and a cylindrical metal casing for said resistance unit mounted on the lower end of said outer member, said cylindrical casing extending radially beyond the outer tubular member to form upper and lower heat radiating surfaces.

3. An electrical heating unit adapted to be removably positioned in a liquid container, said unit comprising concentrically spaced inner and outer tubular members mounted at their upper ends in a closure for said container, said inner member beingl formed of electrical insulating material and said outer member of metal, a body of insulating material mounted in the lower end of the inner member, said body having radial arms merging at their outer ends into a continuous band, an electrical resistance unit supported in said arms at points radially beyond said tubular` members, a cylindrical metal housing having upper, lower and side walls enclosing said band, said cylindrical housing forming a radially enlarged continuation of the outer tubular member and being concentrically spaced from said band, and split rings of cork interposed between said band and the side wall of the cylindrical housing and between said inner and outer tubular members.

4. An electrical heating unit adapted to be removably positioned in a liquid container, said unit comprising a tubular member of insulating material mounted at its upper end in a closure for said container, a porcelain body having a hub portion mounted in the lower end of said tubular member with arms extending radially from said hub and merging into a peripheral band, a metal housing mounted on said closure and enclosing said porcelain body and tubular member, an electrical resistance element supported in the arms of said porcelain body, lead wires connected to said resistance element and extending through said tubular member to the upper end of the latter, and split cork rings interposed between said band and housing and between said tubular member and band.

5. An electrical heating unit adapted to be removably positioned in a liquid container, said unit comprising a metal housing mounted at its upper end in a closure for said container and terminating at its lower end in a radially enlarged cylindrical portion, a tubular member of insulating material mounted at its upper end in said closure and extending downwardly within the housing to said enlarged cylindrical portion of the housing, a body of porcelain secured in the lower end of said tubular member and positioned in the cylindrical portion of the housing, said body consisting of a hub portion with radial arms merging into an annular band, an electrical resistance element supported in said arms, a rib on the upper surface of said hub, binding posts mounted in said rib and connected to said resistance element, lead wires attached to said binding posts and extending through said tubular member to the upper end thereof, and split bands of porous material interposed between said tubular member and housing and between the cylindrical portion of the housing and the band of said porcelain body.

HARRY M. PARMLEY.

REFERENCES CITED The following references are of record in the tile of this patent:

Number 6 UNITED STATES PATENTS Name Date Schindler-Jenny Apr. 28, 1896 Leask Apr. 2, 1901 Ovington Feb. 11, 1913 Naujoks Sept. 14, 1926 Johnson June 28, 1927 Welcomer July 10, 1928 

